The Big Gun Eco Series was designed with a few things in mind, performance, power, sound and craftsmanship. The Eco Series delivers these things all without hurting your wallet. Made for most popular dirtbike models, the Eco Series is made from .049 stainless steel tubing and a 6061 brushed aluminum muffler canister. All Eco Series Exhausts are slip-on systems only. Fits Yamaha Raptor 660 (01-05)